Samsung QD-OLED S90D / S94D vs TCL C8K

In the HDR effect category, the Samsung S90D delivers remarkable performance. On the luminance graph for up to 10% of the window, the television surpasses the 1000 nits mark, which is a notable achievement. However, in the film scenes we tested, these values were slightly lower. In scenes with fullscreen sun glare the brightness drops to about 500 nits, but this is still considered a very good result. It is also worth noting that this model stands out due to its very high colour gamut coverage, thanks to the QD-OLED panel, giving it an edge over televisions with WOLED panels, which cannot achieve such a wide spectrum of colours.

The TCL C8K is a truly bright television. In synthetic conditions – that is, during brightness test patterns – it was able to achieve even 3500 nits of peak brightness in movie mode. This is an impressive result that brings the C8K close to the market leaders, at least in terms of panel brightness. More importantly – these are not just numbers on paper. In films with a lot of bright scenes, such as Life of Pi or The Meg, the brightness clearly exceeds 1000 nits, providing a real sense of HDR effect. The picture in such moments looks very dynamic, colours are vibrant thanks to excellent colour gamut coverage, and lights are spot-on and intense. Just as it should be.

However, this does not mean that everything is perfect. Similar to the contrast tests, compromises also arise here in more demanding scenes. In sequences with very fine light elements – such as stars in the night sky or reflections in dark rooms – the local dimming algorithm can… get confused. Instead of bringing those details up, the television sometimes decides to significantly dim them – to a level of around 300 nits – to maintain blacks. On one hand, this is quite a reasonable approach (better deep blacks than a grey/blue screen), but on the other hand – there may be moments when certain elements of the picture become hardly visible or even disappear into darkness.

TEST UPDATE (20/08/2025) : The brightness control algorithm in this model is quite problematic – an attempt to calibrate the picture so that it does not drastically overexpose the brightest scenes results in unnatural shifts: an improvement in one area of the picture leads to a deterioration in another. The television may achieve slightly higher brightness measurements, but in practice, this comes with a highly oversaturated image that looks very unnatural!

For the sake of order, we provide the brightness values without this adjustment:

1. 1463 nits

2. 640 nits

3. 1368 nits

4. 468 nits

5. 1025 nits

The Samsung 65" S90D with a QD-OLED panel has been tested in Filmmaker Mode, which the manufacturer has used for years to deliver optimal picture settings. In this mode, the TV offers a very good image, but there are some shortcomings worth noting.

In terms of white balance, viewers may notice a red dominance in HD content, which can make skin tones appear unnatural and create a warm overall scene, potentially affecting immersion. This issue becomes more apparent in scenes where subtle colour differences are important. The same effect can be observed in 4K HDR content, though the red shift is less pronounced. This shift can prevent certain details and colours from being fully realised, diminishing the naturalness of the image.

As for contrast, the gamma performance is decent but still has some issues. The gamma values fall short of the reference level of 2.4, resulting in bright areas of the image appearing washed out and dark areas lacking detail. This limitation can make certain scenes feel less dynamic and impact the depth and richness of the picture. However, the EOTF curve for contrast in 4K HDR content performs well, showing the TV's ability to handle differences in brightness. That said, these values still fall slightly below the ideal range, indicating room for further optimisation.

Overall, the Samsung S90D in Filmmaker Mode offers solid colour reproduction, but some adjustments are needed to fully unlock its potential, particularly with different types of content.

In the C8K, a new picture mode has appeared: Filmmaker Mode. This is something we have known for years from televisions of other brands – a mode designed to deliver the director's vision as faithfully as possible, without unnecessary image enhancements. Unfortunately, with TCL, this still seems to be at a stage 'in need of improvement'. At first glance, the screen appears too warm – the image leans towards reds, which may not appeal to everyone. The white balance was significantly skewed – the screen looked distinctly warm, and the red colour dominated almost every scene. There was a lack of blue, which resulted in an unpleasant yellowing and distortion of the image. But that’s not all. Regardless of whether we were watching regular television, YouTube, or films in HDR – the television had a clear tendency to excessively brighten the image. In the gamma and EOTF graph tests, the lines, instead of sticking to the pattern, strayed, which in practice translates to an overly bright and less contrasty image. Additionally, in the colour reproduction tests, there were noticeable deviations – on the colour wheel, certain points were even 'off the mark'. It must be said plainly: Filmmaker Mode in the C8K in its current form is not very filmic.

The quality improves more than anticipated after calibrating the S90D television in movie mode. The white balance for HD and 4K HDR content has been fine-tuned to near perfection. While minor imperfections are still noticeable, they are subtle enough not to significantly impact the overall picture quality. Colours have become more cohesive, promoting a natural reproduction of details, particularly in scenes where precise colour representation is essential. It’s important to note that this particular model, in this size, uses a QD-OLED panel, which offers a broader colour gamut compared to other versions of this model equipped with a WOLED panel.

The contrast has also seen a marked improvement. After calibration, the gamma chart is much closer to the expected curve, resulting in a better balance between the bright and dark areas of the image. The EOTF curve, which previously indicated issues with overexposed scenes, now shows significantly better results. This improvement allows for greater preservation of details in the brighter parts of the image, particularly in HDR content.

After professional calibration, the TCL C8K has made a huge step forward. In SDR content, we managed to almost perfectly set the white balance – the screen has finally stopped being too warm and has acquired a neutral character. The gamma curve, responsible for the way brightness is reproduced, also looks very good now – the image is more consistent and realistic. We also improved the white balance in HDR content – within the limits that the television itself allows. Unfortunately, the C8K still interprets brightness management somewhat "in its own way." When we look at the EOTF chart in films, it is clear that the television brightens entire scenes more than it should. Before calibration, this effect was really troublesome – now the situation looks much better, although it still falls a bit short of perfection. This, however, is a limitation of the device itself, which – despite our efforts – does not allow us to fully tame its nature.

The television excels at smoothing tonal transitions, allowing colours to blend seamlessly, resulting in a natural and fluid image. The built-in noise reduction feature can further enhance these transitions, useful in certain situations. However, it is important to note that activating this option may overly smooth out the desired film grain structure, potentially compromising the authenticity and atmosphere of the image. Therefore, caution is advised when using this feature, to maintain the character and depth of the content.

The S90D model handles lower-resolution materials effectively, as demonstrated in the displayed image. The model's silhouette remains sharp and naturally reproduced, with fine details preserved. Additionally, the branches of the trees are well-defined, free from any visible jagged edges that might otherwise degrade the image quality. Thanks to efficient scaling, even lower-resolution content appears attractive on the screen, which is sure to please users who rely on a variety of content sources, such as standard cable or antenna television.

How does the TCL C8K perform with lower quality content? One could say: reasonably well, though without much enthusiasm. The television offers a tonal transition enhancement feature, which aims to smooth out unwanted gradients. In practice, there is a slight improvement, but it is not at a level that will eliminate all imperfections. The feature subtly softens harsh transitions, but does not perform miracles. Film grain is not completely suppressed, and gentle banding on grey backgrounds can still be noticeable. But perhaps that is for the best? – at least the image does not lose its texture or depth, as can happen with televisions that overdo digital processing. When it comes to upscaling, or enhancing the quality of images from lower resolutions, the C8K performs quite well. The picture is sharp, and details – although sometimes slightly softened – remain readable. However, it is not at the level of the best image processors from the competition. On the plus side, it is worth noting the lack of overscan issues, which is the artificial trimming of the image that can still surprise in some models from other brands.

The S90D TV, featuring a 120 Hz refresh rate matrix and up to 144 Hz in the appropriate PC configuration, delivers excellent motion fluidity. Samsung highlights a range of sharpness settings on a ten-point scale, allowing users to fine-tune the display to their preferences. In UFO tests, the OLED matrix showcases its strengths by eliminating any blurring. The ultra-fast pixel response ensures dynamic movements are faithfully reproduced.

Similar results can be seen in other sizes of this model with a WOLED matrix, which also offer outstanding image fluidity. Organic technology, in this case, is considered among the best on the market. The S90D image, regardless of the matrix type, is exceptionally sharp and detailed, making this television perfect for dynamic scenes, whether for gaming or sports broadcasts. Additionally, its refresh rate and sharpness capabilities guarantee that every movement is smooth and natural, satisfying even the most discerning users.

If you are planning a weekend with the Champions League or a marathon of F1 races – the TCL C8K won't let you down. The television is equipped with a 144 Hz panel, which means it should handle fast motion well by definition. And indeed – it performs very well. The fluidity of motion is at a very good level here, and the "Motion Clarity" feature with two sliders (motion blur reduction and flicker reduction) makes it easy to adjust the effect to your own preferences. Want to smooth it out a bit – you can. Prefer a cinematic look – no problem.

The S90D television is an excellent solution for gamers, offering a range of advanced features that elevate gaming quality to a new level. Equipped with HDMI 2.1 standard, the model supports modern technologies such as VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Thanks to these solutions, the image is incredibly smooth, and the response to commands is instantaneous, which is crucial in dynamic titles. Additionally, the S90D supports HLG (Hybrid Log-Gamma) as well as G-Sync and FreeSync image synchronisation. This enables a perfect connection with Xbox, PlayStation, or PC, eliminating issues with tearing and stuttering. The built-in operating system offers the Xbox Game Pass app, providing access to a vast library of games directly from the television. This solution makes gaming even more convenient and accessible. The Game Bar feature provides quick access to essential information, such as current settings, performance statistics, and the ability to adjust image options. This allows for on-the-fly display parameter modification, which is extremely useful during intense gameplay. Despite lacking support for Dolby Vision, the S90D still offers excellent HDR image quality, allowing for full utilization of the potential of games and movies. As a result, the S90D represents a unique combination of modern technologies, outstanding image quality, and intuitive features, perfect for any gaming enthusiast.

TCL C8K offers practically everything we could expect from a screen for gamers. It features variable refresh rate (VRR), automatic game mode (ALLM), Dolby Vision in games, and a correctly functioning implementation of HGiG, which helps preserve the creators' intentions in HDR titles. The television also supports 120 Hz at lower resolutions without any issues and can even display an astonishing 288 Hz in Full HD – a value that is sure to please fans of dynamic shooters and racing games on PC.

We also find the GameBar – a graphic interface reminiscent of an elongated Nintendo Switch console. It is thanks to this that we gain quick access to information about the current game mode, frame rate, HDR format, and other details that really make life easier for the gamer. Of course, we couldn't resist and launched a couple of races in Forza Horizon on the C8K – and we must admit, it looked and performed really well.

However, there is a slight drawback – in such a fast and evidently gaming device, it is somewhat disappointing that the manufacturer opted for the implementation of only two HDMI 2.1 ports. For some users who utilise several next-generation consoles and, for example, a soundbar with eARC, this might be a certain limitation that is hard to overlook.